QUOTE: "It has always fascinated me how long journeys can change people for the better. I am just very curious about places that people rarely see."

Tom Marshburn has already climbed some of the world's tallest mountain peaks, but he's determined to go even higher. For him, space is the ultimate summit.

Marshburn, a medical doctor, has been selected to train as an astronaut mission specialist beginning this summer, as part of an astronaut class fully focused on fulfilling the new Vision for Space Exploration. He is already a flight surgeon working at NASA's Johnson Space Center in Houston, where he will also do his astronaut training.

"It has always fascinated me how long journeys can change people for the better," he says. "I am just very curious about places that people rarely see." He is a "big fan" of the author Jules Verne, who often wrote about travel adventures in novels such as Around the World in 80 Days.

Dr. Marshburn, who grew up in Atlanta, could write travel books of his own. When he was 19 years old, he backpacked all the way from Canada to Mexico. His 3,400-mile trek took him along the Pacific Crest Trail, which runs along the backbone of the Cascade and Sierra Nevada mountain ranges. He says he has climbed mountains all over the world, including Mount Aconcagua on the border of Chile and Argentina. It's the highest mountain in the Western hemisphere.

"Now, I would be very excited to fly into space, particularly to the moon or Mars -- or to be part of the planning process for those missions," he says.

Dr. Marshburn, 43, says his family is excited about all of the adventures that await him.

"My wife is very excited, being a fan of the space program herself, and my older brothers and sisters are thrilled that their 'little brother' made it," he says.

Dr. Marshburn has an 18-month-old daughter, whom he "loves to play with." He also has a cat -- a girl -- named Steve. "We thought of the name before we got the cat," he says.

Through the years, his patients have been among his inspirations, when they have "successfully overcome incredible challenges." He also credits two college physics teachers, as well as his brothers and sisters, for helping him along.

Dr. Marshburn was born in Statesville, N.C. and attended Davidson College, earning a Bachelor's degree in physics. He earned two Master's degrees, first from the University of Virginia and later from the University of Texas Medical Branch. His M.D. is from Wake Forest University.

Through his work at NASA, Dr. Marshburn lived in Russia for two years, working with the International Space Station program. He also served as lead crew surgeon for the 7th expedition to the Space Station.

Even with all the miles beyond him and all of the adventures ahead, Dr. Marshburn says that, for him, "learning is the most exciting journey."

Mission Specialists: Bachelor's degree in engineering, biological science, physical science or mathematics and minimum three years of related experience or an advanced degree. Vision minimum 20/150 uncorrected, correctable to 20/20. Maximum sitting blood pressure of 140/90. Height between 150 and 193 cm.. Due to a surplus of astronauts and a dearth of missions, NASA cancelled the planned 2002 astronaut selection. The next call for applications was made in May 2003, with a due date of 1 July. 'Educator astronauts' were especially requested, and 1100 applications were received in this category. The final selection was two pilots and nine mission specialists; nine men and two women. Given the drastic reduction if shuttle flights and ISS crew size planned for the post-Columbia disaster period, the chances for astronauts from this group flying in the next decade seemed slim indeed. Also training in this group were three NASDA astronauts from Japan.